Conventional data storage devices generally fall into two categories. The first category is electronic, solid-state memory devices such as read only memory (ROM) and random access memory (RAM). These memory devices are generally fixed within a computer. They are not intended to be removable or portable so that they may be used on different computers to permit the transfer of data from one computer to another computer.
The second category is surface-based data storage devices in which data is stored, typically, on the surface of a disk or tape. Examples of surface storage devices are magnetic disks, CD-ROMs, and USB disks coupled externally to the computer through a mechanical drive mechanism to be installed in, or coupled to, the computer. Accordingly, the magnetic disks or CD-ROMs are removable and portable.
The USB disk includes a flash memory device therein to store real-time data, voice, and audio and video data. An example of the USB disk is disclosed in U.S. Pat. No. 6,148,354. FIG. 1 is a re-creation of FIG. 5 of the above patent and shows a computer host system having a USB flash memory device.
Referring to FIG. 1, a flash memory system 42 includes a host platform 44 for operating a non-volatile USB flash memory storage device. The host platform 44 is connected to a USB flash memory device 46 through a USB cable 48 and is connected to the USB cable 48 through a USB host connector 50. The USB flash memory device 46 is connected to the USB cable 48 through a USB flash device connector 52. The host platform 44 includes a USB host controller 54 for controlling and managing USB transmission on a USB bus. The USB flash memory device 46 has a USB flash memory device controller 56 for controlling the USB flash memory device 46 and for managing the interface with the USB flash-memory device 46 and USB bus, the USB flash memory device connector 52, and at least one flash memory module 58. Preferably, the flash memory module 58 includes a flash memory module array in which data is stored.
When the USB flash memory device 46 is coupled to the host platform 44, a standard USB process is established. During the USB process, the host platform 44 configures the arrangement of the USB flash memory device 46 and the data transfer mode with the USB flash memory device 46. During the course of the configuration, the host platform 44 determines the overall storage capacity of the USB flash memory device 46 and determines the remaining, unused, capacity. In this manner, information related to the storage capacity of the USB flash memory device 46 is determined by directly connecting the USB flash memory device 46 to the USB host connector 50 of the host platform 44.
Unfortunately, the above conventional method of perceiving the data storage capacity of the USB flash memory device 46 has disadvantages in that it is required that the computer system of the host platform 44 must be powered up and the USB flash memory device 46 must be connected to the USB host connector 50 for determining storage capacity information of the flash memory device 46.